A vulnerability ( CVE-2025-21176 https://www.cve.org/CVERecord ) exists in DiaSymReader.dll due to buffer over-read.
Per CWE-126: Buffer Over-read https://cwe.mitre.org/data/definitions/126.html , Buffer Over-read is when a product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
This issue affects EOL ASP.NET 6.0.0 <= 6.0.36 as represented in this CVE, as well as 8.0.0 <= 8.0.11 & <= 9.0.0 as represented in CVE-2025-21176.
Additionally, if you've deployed self-contained applications https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.
NOTE: This CVE affects only End Of Life (EOL) software components. The vendor, Microsoft, has indicated there will be no future updates nor support provided upon inquiry.
No Active Exploit Signals
CVSS Base Score
8.8
HIGH
Exploitability:2.9
Impact Score:5.9
EPSS Probability:0.72%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
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SSVC Action
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CISA BINDING OPERATIONAL DIRECTIVE (BOD 22-01)Mandatory Federal Remediation
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